[PATCH] D128315: AMDGPU: Don't fold cndmask into compare in different block

[Matt Arsenault via Phabricator via llvm-commits]

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We were hitting a liveness error if the register use moved into the
compare's block if the register needs to be live out. Handling the
liveness update across blocks is much more complicated and probably
 not worth it. I doubt this pattern appears in real code across blocks.
I'm also not completely sure if this was correct in the presence of
loops anyway.


https://reviews.llvm.org/D128315

Files:
  llvm/lib/Target/AMDGPU/SIOptimizeExecMaskingPreRA.cpp
  llvm/test/CodeGen/AMDGPU/opt-exec-masking-pre-ra-update-liveness.mir
  llvm/test/CodeGen/AMDGPU/optimize-negated-cond-exec-masking.mir

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